The present invention relates to a wrench for automatically selectively turning conventional polygonal nuts and locknuts.
By way of background, in the automotive industry, wheel rims are mounted on axle studs by means of a plurality of nuts. In certain automobiles, where the rims and tires are very valuable, a plurality of conventional polygonal nuts and one locknut are used to secure the rim to the axle studs. The polygonal nuts can be removed by any conventional wrench. The locknut can only be removed by a specialized key-type of wrench because a conventional wrench cannot grip it. The foregoing arrangement guards against unauthorized removal of the wheel rim from its associated studs.
In the past, insofar as known, the polygonal nuts were installed by means of a first wrench mounted on a pneumatic gun and the cylindrical locknuts were installed by a second wrench. This procedure required more handling and effort than if a single wrench could perform both tasks.